Bituminous roadmaking material



United States Patent 2,906,633 Patented Sept. 29, 1959 ance to pressure and wear which is regarded as inadem5,633 quate and they must therefore not be used, although BITUMINOUS ROADMAKING MATERIAL mf gmfig z m% f:g $g; 5 oily impregnating agent generally used hitherto into an Bern, Switzerland, :1 company of Switze l d aqueous emulsion, m which water suitably becomes the dispersion agent and the oily constitutents the dispersed N0 Drawing- Al'phcahon July 1956 phase. Water glass is used to stabilize the emulsion. serialNo' 599686 This water glass component not only has the task of Chins Priority, li flon Switzerland A t 16, 1955 keeping the emulsion stable; in another sense, too, it plays a role which is of decisive importance for the invention. claim (CL 106-82) This role is based on the fact that water glass, on coming into contact with air in the mixture, is subject to a The present invention relates to the production of a chemical reaction, as a result of which the silicic acid roadmaking material and is characterized by the fact contained in said water glass is cleaved, simultaneously that the bituminous for the road surface has a binds the emulsion water to it, dries quickly and hardens. mineral dust added to it which has been impregnat d The rapidly solidifying silicic acid, however, mixed with with an aqueous emulsion of at least one hydrocarbon, the hydrocarbon component, enters the fine surface pores wh emulsion contains Water 81355 as a Stabllller, and of every grain of dust and envelops the latter like a thin further characterized by the fact that the impregnation is coating which, because it is enriched with silicic acid, efiected with the admission of air. increases the dust grains resistance to pressure and wear,

It is known that motorized road trafiic, which increases which resistance was inadequate in certain cases of conin intensity and Speed from Y to Year, @9115 f r greater ventional road materials. The increase in resistance of r lf- Among the measures that contl'ibutfi I0 the grains is due to the fact that those grains undergo proving this road safety a e a l o e P 0f g an extensive hardemng process and thus can be made l roadway Surface asfough a5 P P and 0f keepmg to meet the requirements for the present purpose. It p rm n n y and y rough in y Weather, at The composition of the emulsion is advantageously y temperature and i yp l adapted to the adsorption and absorption properties of a u IYf Y 0f f t fi gfg lgii gs a is io 'tfi tg th the dllisett to be flilmpreilgnatedfigy way of example, it may ma 5 aces 0 e 1 0 e e v ween e o owm ts: mixture a certain proportion of fine mineral dust which m g P t by weight has been previously impregnated with an impregn ing Bitumen containing flux oil 30 to 40 material selected from the group of hydrocarbons R C Tall oil as emulsifier 0.3 to 1 dust, ground slag, ground clinker, cement, hydraulic lime, Water glass as stabilizer 20 to 10 ash and the like can be used as the dust. Suitable imw n-, 49 7 to 49 pregnating agents are, for instance, hydrocarbons occuring as waste products in petroleum distillation, 1:11 Totals 100 100 as bitumen, heavy oil, gas oil, kerosene or gaso e, o and those which are obtained as by-products in the gasi- 40 i'g m z i g fication or carbonization of mineral coal, such as tar and hi e i a mipmgna 1 tar oils. Mixes can be produced from both groups and s p to e to e @Pregnate can so e a apte to the adsorption properties of the dust; it may, by way used for the aforesaid purposes of exam 1e v betw 5 and 15 at b ht Mixes of one or the other group are generally used as related 5 i fi a1 t of the y welg mprqgnaung f m the known mipregqatmg i On completion of the impregnation process the dust, the hghter oil component promoting hquefaction and impregnated by way of example in an open mixing drum therefore also being termed flux oil or flux agent. The is already in the form of a dry powder which can 223231: amaze: pmdgmbaesggmgdmdh g use an can now, as ea mention e a to e fi g z d t l'f t h fiag g zfsgd i tfi road surface mix and produce the desired increase in 0 e 115 an 0n 5 therou essoftheroadwa. tended to facilitate impregnation at low working tem- It understood mg; h impregnated dust pieratifirez. at: thgfpggofigtgoagfplgxflzgegztflw fillet-hri thus pgdoducedhlmlay alsobbe bconsgered at; an intlerereor, m in ructwcma erou ton emaret more and more so that finally even cold impregnation is fg f of h i i i i Possible, impregnation can bfl efiected, if need be, Various changes and modifications may be made with- Without Pfeheating the dust and the impregnating q out departing from the spirit and scope of the present AS these impregnating agents are a a invention and it is intended that such obvious changes stances, the dust to be impregnated must dry an and modifications be embraced by the annexed claim. necessary, predried even when the cold process is ap- I claim: plied. Furthermore, certain types of dust tend to repel A bituminous road making material comprising an all oily substances so that not only is the impregnating emulsion for impregnating mineral dust consisting essenprocess delayed, but the impregnation itself is inhomotially of 30 to 40% by weight of bitumen and a flux oil, geneous. In addition, some types of dust, among which water, 0.3 to 1% by weight of tall oil, and a mineral are to be found even certain rock dusts, have a resistas dust to be impregnated, said emulsion further containit is diflicult to find a substitute in certain areas which do not have any suitable rocks.

All these drawbacks are eliminated by converting the 4 ing between 20 to 10% by weight of water glass in said 2,498,862 Pettiean Feb. 28, 1950 emulsion with said emulsion being under the influence 2,568,850 Fasold etal Sept. 25, 1951 of air, whereby said water glass in said emulsion binds 2,670,332 McCoy Feb. 23, 1954 said water in said emulsion to thereby facilitate rapid drying of said mineral dust in finely powdered form 5 FOREIGN PATENTS while preventing mineral dust conglomeration. 861 Great B i i 190g 474,163 Great Britain Oct. 27, 1937 Refmms 111 fins P 667,054 Great Britain Feb. 20, 1952 UNITED STATES PATENTS 683,170 Great Britain Nov. 26, 1952 1,956,779 Sparks May 1, 1934 

